SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'e271592f44da8517cd99d5712775cb2a6fd704f9fc21658fc3bd0f5341931a76' 
  AND token = 'wldpcpO+MswGsuOTAkgSVcTErXDEfsDNZqGqcpbfTmM=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00014

JSON explain

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