SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '16f213b2abcd31a1d09d7fd646ccb3b7d572805830d4771f87f90fa79bff6657' 
  AND token = 'l0Dl2VzuEWZzoa4rzUKHXZkJijCA5/Lh3t3EBkZt6zQ=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00037

JSON explain

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