SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'f3562cbf0fb0b4a0ec09d05a592fd780e9773cf364ba99e10b35cf8a4371e8e7' 
  AND token = 'MYuAH10LzQQr1RMq40O1aj/1/ippJ2SwPO9vr/Bd2nQ=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00019

JSON explain

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