SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '938cbf89b4d1bb9aef63226033710f7f2235ffba9269d7846ade1f2c2f5c4664' 
  AND token = 'iL99gWwHHApeo1eV/STUUNoivsGXJjfcu5EwRjvBQlI=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00028

JSON explain

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