SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '16ec057ecc03204b6b5c5adea7bff33fa8e198f0dd3d78f72f6caf244d97dd46' 
  AND token = '4noyqiziuPUT3NoIRKJkbP+qxuv5yUqYAZrPLwvbBCc=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00048

JSON explain

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