SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'f72ec8ca684af2c0d4320f1726be9e3c271707b73b26afa5b053d84b4062dcbe' 
  AND token = '1nwYQ47dkmHx/iMTWpt2S+AwInfM2Uz38F9iJr/ApaA=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00022

JSON explain

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