SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'edd2d8795590ba9842e436e2baa903267189904b031c117d786980bee83cf63a' 
  AND token = 'HO1aup2l/SPh7jP/SHmjQLyGqYvvX5MdtCiBbrV6gcA=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00039

JSON explain

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