SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '70eb8aa00dfdcdbd96c567945c52df42d41c6141e1613eca0b8697552bfdb8c0' 
  AND token = 'BmalVzmi62fgOYnwSwPV486vLTPAxTpy83O2vfgFOSQ=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00034

JSON explain

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