SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '735c7fad4df070b7d55a72fdf99b9feec40a9ada9edddc6ac67e45a9ae1a3e25' 
  AND token = 'L6ECX98noRT23pnoLQdK7UHVP40bKem1JLXkmnOGNYc=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00022

JSON explain

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