SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'bd5112f670f279f3bd5a162db07de19f83d3c139b99ad83bb5cf2780b66c0bf8' 
  AND token = 'ODy+aJt4fLKRGwAGtishHmuUkyo4chrkKdZgGhKB4lQ=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00023

JSON explain

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