SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '468c92d46ebc9cc52672a249e9a7b5fdc2030161b1ddb2cf33a918b2f430ca47' 
  AND token = '+Pqu41Y4ceXhTPIpwiQiAPf/+mO/dVkXVKJdFvpRTmg=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00026

JSON explain

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