SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '54ff7619d4f7e422af906c573c6640d06342b1b728a5f85249b88e2c30d30c11' 
  AND token = 'Uk46nfloLSx8pZA31crHOqDHTVKgGVirTvJFM6uj6E8=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00018

JSON explain

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