SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '5522660cff33edb8d522ded76d4513e4a9800e5086f0a3f13367dd482b103548' 
  AND token = 's2fhe08WIiRrUr58PkFZZVMSMPi3LaGsXdurIS5Ebg8=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00041

JSON explain

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