SELECT 
  1 
FROM 
  cscart_aprillock_keys 
WHERE 
  key_id = 'f8a1a6aff4e677bd826b801d43fc5c2479ab1396c59b6e9998f2308bb93e2178' 
  AND token = 'heuE1XqlUQkY+BJlECnxEl04BIKMJYBwBMP6gpXNTsU=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00032

JSON explain

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