SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '8f14dae3afc01074aa72ebce3c5887e310e44b0abac20141840861a5d97c6f37' 
  AND token = 'BvwZ4TK9LpREA4mDqUOOUUwI1oapkOMMbYHMg13p16k=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00044

JSON explain

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