SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'd76790f149f8bc62b32e2b627312d3dec02e71a82ba73465de8a5893b5723afa' 
  AND token = 'JlWks3NCxXu6B3SvtiiD/pnJ/BfB8+N6032mv0fbUQw=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00043

JSON explain

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