SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '72c780f8ada06d8d4329953c148d2ec3d15658697ebf42cc07fe847f90a1859f' 
  AND token = 'c0gpc5+HdynLZBQrMCqSn46vuRvuFcB4wEsz8TiNiFU=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00034

JSON explain

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