SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '09bc767f9fa008c4b55ace88d62c896283acc9cbf257f63f2ffd1aade11d8809' 
  AND token = '+BxqIR8xNMx48pibxLQE7NAxCzIUwv1+FWKBfP9vfYk=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00033

JSON explain

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