SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '58c6cbf368c1bfc87964e5220360994538385d84f71ac2692915f42a46b99024' 
  AND token = 'ztQVKgWpUbh3htgpyxA51Uqm+hhUkc8pwDIiFaoGsyo=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00043

JSON explain

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