SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'f3866abbffce1c5de4d308a1e3ff32f7c50205c3d7e8f7435cd16e6e6fa99d1a' 
  AND token = '65EfFXEnRv33kdXKgL4Sk+VUwkQExNIZXXdJy5AgXGk=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00044

JSON explain

{
  "query_block": {
    "select_id": 1,
    "table": {
      "message": "Impossible WHERE noticed after reading const tables"
    }
  }
}