SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '7b5064b62fa8a1390a5b1b90c4cbaa689168d2be2342df6fd3fe20e1c5ae6a10' 
  AND token = 'j1mOZKHGTf7xGJB8WTq83EhG3ArJzfaxVsrgvfmwgKE=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00016

JSON explain

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