SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '923fc3b624dbf2bc11b15c56f564485ff11965df7adc03b94538247ed14898ea' 
  AND token = 'RtHHwytwuIBuY4EGvfaKcB21ukxvQeCPEiv/Xan4ED4=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00029

JSON explain

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