SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '7081ea843d792f298faa6cc355fe84355a37bb26aaa58c6550bc39dee363a79c' 
  AND token = '7JgPKhqrmAYbekT5pBb36AGkSRqgkqguClDWXJNXG+Q=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00031

JSON explain

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