SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'ce0c85196293f5ec89323039c1c275b1b0fc1cd396787ef7cedb34f393a94b52' 
  AND token = 'de2/saDMTelRGMJDK7fBxF8ebgji8qE4DZTuZ2OrxBs=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00027

JSON explain

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