SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'e2fff22ac9a7e44d1ba36d12e43e07dda2c291975f042800048b8748ec793dc4' 
  AND token = '+nRp2iqgdH1WgNkY5ENBEbte+Ka5Tl/XbRn/jvUu6J4=' 
  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"
    }
  }
}