SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '36d1a3cb65a24fc24da39937abd189e4d4428876b96629b7a5e16aaf897ce90b' 
  AND token = 'Rjqcwsn8TS74LDZ6KqNDJU2psYtMK5b1mWAUh2Bzqjw=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00045

JSON explain

{
  "query_block": {
    "select_id": 1,
    "message": "no matching row in const table"
  }
}