SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '90879338ee36345371da732f71755f8045bb890bcaedd4295be19c1db9171cb1' 
  AND token = 'ijBL2BuHpPAzouKIh03RqB8mZgNlEMTX/SwEJiSNF3M=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00040

JSON explain

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