SELECT 
  1 
FROM 
  cscart_june_setuplock_keys 
WHERE 
  key_id = '4c4d6ae81dda138d543a084d378106b1ca0c30d128b894c392ae4528d519df7f' 
  AND token = 'lr9yPeSvl1ffPBsQxCcPGRuQrBT7QmywI2l0t3ygHLY=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00026

JSON explain

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