SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '8952af7bfe7432eb6a3460e09800142be94bc11dd422e75d41bc9e40846fbd18' 
  AND token = 'YJPXwVkMlsDrmYKYqeRG1gCxXWA7/lCajYnqgVxp3xg=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00030

JSON explain

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