SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '6bf86ba6b185d1d123f2a8904fb5af25bfbaa3cea5958637100baa895328ffce' 
  AND token = 'Oy7XC3H4Oc3VFgwF+jvgOmKSzKWbxxaIVlSBhlG0Dyo=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00019

JSON explain

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