SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'f2e228346ecb0ee8d3ce50e65703fd2709f506bf554e38fddcebfd122d0b1939' 
  AND token = '2OksTeig65aCH1NGtmonAIVxoJkBkU7FUrUTBXT9RXA=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00027

JSON explain

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