SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'd2f4e6445505e1f30df4e3f9736012c1d11fa2f940b805c0ad5db95a8062edb0' 
  AND token = 'OTuQ/25khOywjPlsInNTCBpaB8xflwQCmAIrzyNvn0o=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00046

JSON explain

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