SELECT 
  1 
FROM 
  cscart_aprillock_keys 
WHERE 
  key_id = '46939333bc29800f807bc5111d84b0411508549453dfa0d70d76dbff5cfd2216' 
  AND token = '6lpk5uEVBxPJ8n+VjJNLgHOm1BQ818jhNW7YQlD+aEQ=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00038

JSON explain

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