SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '6fdcd817080f5569089a96829edc8afed83586be0c8438f19a12b8d433f611db' 
  AND token = 'gVVP4tPBmUNWW6baxHQDLf1zXa6fPY/digXugcKXP6s=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00039

JSON explain

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