SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '7e596116fddb89f0e9e612ee0ecf497a6dd3bf5a0057479c5f8d37584d9b41f5' 
  AND token = 'qhlqrIzJ67zwn/p+GBZO4JvaeQU5oZOq+rr9Reh6Lt8=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00018

JSON explain

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