SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '317dbb2c9f2090e5e6e2e1128dfde577e96446d65c9cc1888c8e2e2e2cf57983' 
  AND token = 'CJksUhyjGXh+7ORXhYXfd9TnenXUSxm7oP5JwKSkf5A=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00023

JSON explain

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