SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'ce93da03eabf848b1ed1e4b0061ff93fbc6cf86b1eddaa5154bfe89aecaf792d' 
  AND token = '5yZ8QO8WJ5PoFpHcW1luiFYgKGsX2KwzJ04ivIDVBdw=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00024

JSON explain

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