SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'a38b82a91c2873fb1857fc1e048e1294859418b59575010da8d3cd609bc84552' 
  AND token = '60USMUyCqauXHtjYqRBh1uzNWGsY7KZJYpmMKTMjcA0=' 
  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"
    }
  }
}