SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'bb18c9fc77584d290c48413da31259407e2fbaf16785f791570dd54c34ca6eb3' 
  AND token = 'eeNmkkgjBiNsUesjtdTynn4jpSkV1u9PIw/+TWjYH3o=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00023

JSON explain

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