SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'b053ab8cf0b760e26894e15061818afb7eb0fac54e4b17a738f37ca05298a63c' 
  AND token = 'LIuMNmTvwE6nkZEx3/+isHYYGDio4EIRASiqbILuHxM=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00032

JSON explain

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