SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'c14731aaa675e7c409b400dd23430112df2b4dc688b22f88c6b6c7ae48b60f4d' 
  AND token = 'wA3CorF0MEgjYW65/nNhmaYKVyer+KBrVGETaY5F2xQ=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00019

JSON explain

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