SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'a92c575c74958326e402a4b405be2bfa626985d4e905854bdb3343b234f53a4d' 
  AND token = 'GCQYPxxl6dEyeGvmwD8gyrYampgb7Fob6cq2U76euB4=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00047

JSON explain

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