SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '95d8511d107cbebbb028fe477cb8ac6eb7634993a8231f979462c4163f3726c4' 
  AND token = 'EOAIHsWGcizFHfDv6yGBSVvbo8PnWIR5OwR/NKMu/Vc=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00025

JSON explain

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