SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '539fd75f9bd292dd24cd680da0d2bf8205f1e47b55fbafba261d30aca0186287' 
  AND token = 'uBWX7mpnGBCfCKCAzXtCV1fmYxjXeLxBvIqoxqUlhCs=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00030

JSON explain

{
  "query_block": {
    "select_id": 1,
    "message": "no matching row in const table"
  }
}