SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '0cd915826ad95817bad5b2d85deaaef398cc17bc421e2092f5bee5dcfe78a09e' 
  AND token = 'A1FRflh3n0m9ftMA14Fhu/I2rim5AjDfo5S0w7qM+CI=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00042

JSON explain

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