SELECT 
  1 
FROM 
  cscart_aprillock_keys 
WHERE 
  key_id = 'ceb4864a318a8fb737745a26ad8df8764162e6954489e15864545868c903dc45' 
  AND token = 'jF4Qz/vFt95DmKxuBnvx9Bamq1KSfAIXclJjzlhUC9s=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00038

JSON explain

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