SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'c262b9744057c3154fe645a2cb3c263d3909aa28c3db29392a95a51fd7fab232' 
  AND token = 'DLTv9YrzsIetv/0oyq6UO2hKXnj6fti9/W04q3jEAlI=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00053

JSON explain

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