SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '5595b5b5ed373c33c3569b07d8afc57edd1e1b57536cf021b2a547227c611646' 
  AND token = 'FubmCmzjJJ3krcot34KhCKQn9I0jkZOxyijA6FRvd+I=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00057

JSON explain

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