SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '29ee60758be93108dc392d5b2eee4063577398c33d72fe592d6932b265e3384f' 
  AND token = 'aMaSmGR/hBqHmDvYOZkQMKs3IffkPCcd6+TXzp3lKJo=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00038

JSON explain

{
  "query_block": {
    "select_id": 1,
    "table": {
      "message": "Impossible WHERE noticed after reading const tables"
    }
  }
}