SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '313f061b63d07edf8131300c36f45408e21cc93e557f057ff1194db0cf82dc52' 
  AND token = 'wxZ5FZWxm2H+Ndhv4kbzpuyoiCrlXXBe8O7Cp8+rKXc=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00020

JSON explain

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