SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'da5e5e2764a038f584cbdb6ba4bc27bfb335eff6e041ed16a29eba10a8b29b3d' 
  AND token = 'GDA01SyBjVTx7Zzxe6PlG75I9vu9KMPqnZHqB6wOS7g=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00023

JSON explain

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