SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '986a8437b40a66a9fc96c237c121c1204a51facd6e10151223f4c749940418f4' 
  AND token = 'Xl9o9gJ8Jq4e1wFkT+Zn530td/A9b+U9Rj993htURyk=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00041

JSON explain

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