SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '238091379ee22d3ecf3e69dc1bb35bdff0e68247e51180007eddeb381b1018d3' 
  AND token = 'S7mby7TckviZlzoG95ov+1ljsEc8py1MxhGPs8DD5Ds=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00017

JSON explain

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