SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '7488ea27d10a31870f627933986041d444e10aee7257282462cf0bb53cb97f8a' 
  AND token = 'MvwSes94xefgcgxvY+MUXRhE0xEf5iAUrDdahjsseYM=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00035

JSON explain

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