SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'f2ec62627e85c9d33573a14628165d6461605a3b47c836d601557771ccbdedaf' 
  AND token = 'krjmR12XAlkrv8mi2G342pwtrlEMHcJ4r1oKznJnLAI=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00025

JSON explain

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