SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'f98cf70a848dfe3e0173805c391de73fbb9f4c4880794308467f5f15b66e851c' 
  AND token = '8JIk8sF/2klsfnS82b0laG4/gpMtEgDBIowiyoIBpdk=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00041

JSON explain

{
  "query_block": {
    "select_id": 1,
    "table": {
      "message": "Impossible WHERE noticed after reading const tables"
    }
  }
}