SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'c04e07faeddb385239b48443f785964893481fabf336dad320696958caa22655' 
  AND token = 'tTONSl8QYXyG+d5TiSZULlQl0lnuznri0oBh7Megmvc=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00031

JSON explain

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