SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '8b76bb955f72297c2549a4e94f6c94560d973ec190899c71490bd3409d0051b6' 
  AND token = 'W+qyefZKboGkEFFmI+UdVLAIY/iAs6YoCuzH2Ajm/7g=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00037

JSON explain

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