SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '6450ae96b496bef779d1ec6bb1751d3e2ca1528650c954457cfd76768b14ce1a' 
  AND token = 'UopXVKZpY3skfWEUPW8zhgcn94j6fo6ZKRFhOowCBFU=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00042

JSON explain

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