SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '9fbb824cefd9e8b0c46ec2c58797e42c757b07715542fe93124e75201139855f' 
  AND token = 'RUeLBGT/x49S8liK+gy99mLWot8yrewqh0cIglVStws=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00019

JSON explain

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