SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'e72d805a68df76250c57a9c8eba3e6871959ad92502f38782a3269dec6aba539' 
  AND token = 'oeFiPgfc5jRutuph/WxtkBBZVHJHYZF5mUbjqg+1bPE=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00021

JSON explain

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