SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'acacdebbe01c758b465d6df880d97ef5634c5d0d750cde65c8f11d07120a3108' 
  AND token = '/8vI3KVzrNpHPYDJClXeoo0UuanErw9FDtG+2CYNsEE=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00035

JSON explain

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