SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '6b26c4b24c0dd54591dd6aa751e0a5f1feb7d747f45c0c913dba73c2c4c22dd0' 
  AND token = 'EuSBGKF+zXptRoyRHWyB7iKrWVRPZU4lmKP6scPlStU=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00035

JSON explain

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