SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '46d1607219d9afcd88514a791ec5554033e3e2b488557e8853352ffbb64e1141' 
  AND token = 'vRMqlt909JCk9KnWzJG7u2ZP3ZLB050utlIE/KcNopA=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00038

JSON explain

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