SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'f621f316bd4b0a7961cf140c327ea497064e96074751257429a6c6d62dc2f33d' 
  AND token = 'qCJGyFHj89Q4MoMQUMSheFnYS6QTdCgjfVBDv/nuLXA=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00043

JSON explain

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