SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '411e4f00ff06895e66d276687c9c5ab02e03b76979a4c979c911c0b87fe25a1b' 
  AND token = '4JopqehDD27Sj2m/K3VDummn/bwgwOf3GA+GGW59Ils=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00019

JSON explain

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