SELECT 
  1 
FROM 
  cscart_aprillock_keys 
WHERE 
  key_id = 'fd383b6ee02469fc0fc4904e4ae2581e90a518131d83b201003c3de253bfe1f5' 
  AND token = 'fWSbWgqlUQS3tLab3Bq2813wN5qpfOrsDjH9Bxdj/6Y=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00022

JSON explain

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