SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'da451170db40c18f3f5fce947c238dc65e224374abf892cff035ac0ed6db8f32' 
  AND token = 'FFqiKGJsUjwgAmUc4E56dfqcPAYYHxvGemz/KFr6K9s=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00048

JSON explain

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