SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '2a1be182391714fa3dfcc8c0c0ce18e3fd743189519b58364791a9672b0acede' 
  AND token = 'qn3+TKOo0I3wqcDFErCJSQMdmcyaGZJybJcusohb0mQ=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00027

JSON explain

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