SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '1784f33995131dfb5d0942bc287ef5c5adc1e04285ea561a43cd336cb3cdf030' 
  AND token = 'PTrjiV916XBVjWXCFDeYsetOBJEsNmBzvyfp7m7ULOg=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00044

JSON explain

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