SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '8132b80e80cdcd1da2c72c49a4aa45864a838fe1fbafffe2f0424d226de9de3f' 
  AND token = 'EE7kLMnB/6F3gYGqDTd/FmtBTji5xtcn5Rc+nus47mg=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00038

JSON explain

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