SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'cd46190a93ea16dbff71eb621991085a9cc2a72fd8c4987237af69982eacf172' 
  AND token = 'vNgWHanRUuFoROYztHSHtLgZwnWyAlrVx8DOGuGm6mw=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00029

JSON explain

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