SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'caeea97eb82fd7777df1eb0b1733d82166c948555546ed2701bbf0ca1e5e4a1e' 
  AND token = 'pl8REVooslpvvKiIsWhSutsqCUZmGmlYSfTxSe7uyMg=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00015

JSON explain

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