SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '268955bc95b80878d2718a0f15201cfadc199932e77fc467572acde8101fe968' 
  AND token = 'cpMto6OxQfCjk8O952Z6ziwCXQYqaS1rScavzcusvAQ=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00044

JSON explain

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