SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '65442cf9696ae1f176d825b9cbb4ba1a4c4f61ff452d30b7d21354605d933723' 
  AND token = 'uoZQWGxZ7GYca3EoiZSTOHfJkRtqBPynZNMVW9bFDH0=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00024

JSON explain

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