SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'ee0538472d04c288c949f81cd9d1a565e1c8a52afdd0a39fdb7a440da5578272' 
  AND token = 'eGzCz2Ad60oTANlry8hGtTbZNkzSwbo42Tzqdt9lYMs=' 
  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"
    }
  }
}