SELECT 
  1 
FROM 
  cscart_june_setuplock_keys 
WHERE 
  key_id = '81a2c4d1cd85ec7bee5c9933c0a2da8b8efb930ab1a860f09f661d7198ff55f0' 
  AND token = 'pYIP1NCvvzL7/M+1vnoRGZcNjLU1yoE9uomcVGw6ZfU=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00019

JSON explain

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