SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '0ec3122769dfc5d80b602c61718047401e2dc30c03f536a897ffb79cfaf0853d' 
  AND token = '+KpQNEQHzMggxOgyznuPPWxdPmm4+fgBkKZI8licuWk=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00047

JSON explain

{
  "query_block": {
    "select_id": 1,
    "table": {
      "message": "Impossible WHERE noticed after reading const tables"
    }
  }
}