SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '3624f4731aab4a0646dfbce67db48919abbe71847370990169783fc3b84ff0bc' 
  AND token = 'thwFIlg55ZjPTPqxtp7misIM5IPbv9nEH/c8vqXwkVE=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00046

JSON explain

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