SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'e09646812edaf82c7a02eee43e7b259aa835aafeeb24eda01bea768850074669' 
  AND token = 'UZ7yla0tUKDFdYwOXQClj1w9IIYFwi/tolqCOtCodMk=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00030

JSON explain

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