SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '7332000e4e56e041f58707f728029404accdffbebed81a9547de72944adfab48' 
  AND token = 'zguPBKb40aBrAqLHd20jTm/+guWHTyOihtJIRm9VPJI=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00041

JSON explain

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