SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'ba179f821cf996def8c5630bd5ca151bbfa719a143d29768f2bf4a4eb75dab18' 
  AND token = 'R/vLPFifVyhhpmKVMiuozUqtNfPo5skEPb6Xn9Z/IzE=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00027

JSON explain

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