SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '69dbcb055c36a1c8e2c78b1f115ca4477978266d2fffd226ebcd0f27450f6ec6' 
  AND token = 'yjsdc+lXtPk/XZQi/i2RNvrCbyMql77VNLos4HwI0Mg=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00057

JSON explain

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