SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '811309d388dba2bd39d0cbe4ef76d403b3048c4cf74b6a0a4c79d212eba1e932' 
  AND token = '5oXaFvJkwDEEAVqfNZBLpTL079aYE792zmkoilbAA2A=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00024

JSON explain

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