SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'c59f032b9fb6692eeaadd76bc77faa6909b62a1df714bbc2c19c8d086d5f689c' 
  AND token = 'Y0AwGL/bQ0JVXxWsag1xyTRiyyUQsu05nMeHWrk5rpE=' 
  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"
    }
  }
}