SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '665ba6a6cd285f9102749915f1bd35498a7e3d702840bebfeffeff31c1d95352' 
  AND token = 'o8qXUYzL8yeriYMhIyjC2ghK+Mg38zK/mqC9UugDgU4=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00045

JSON explain

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