SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '566a5ced567c78699387f18b1d584b835b9438cca2fa53051f4f2bca1ddfe34b' 
  AND token = 'pt0CAkJI4bRoSEuN+T1FB60sE7nck+aaJ9ShrkvjNzg=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00040

JSON explain

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