SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '340e69e00cb1619ba8d63ea0e4183f12b6c424777bc0f7929833fdcf072f65b9' 
  AND token = 'NYoTx3hjHw+s5fRDZqP920JWkHmo39yvPRkxaCA3XTU=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00049

JSON explain

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