SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '395b1ed30cd533404a8ae5508b3bfde5e1ddc102985a1c90ef0e6dc6dee71044' 
  AND token = 'eKokMqD60SaLesNAytSHJ8oStQArW8yGWWWIWBRDD1c=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00022

JSON explain

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