SELECT 
  1 
FROM 
  cscart_aprillock_keys 
WHERE 
  key_id = '4d57520fc97ce220193cf72142f653891163ed52ec3ca877442888e6c644d5ea' 
  AND token = 'aGz2gljLGgpzXs4bdGM4w3rVHx2L85/Zqi0vZw9CGSY=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00037

JSON explain

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