SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'e048c9a3a25f359d65c00eb42950abc79d6b3c44ae84b5f898d29b5e87ae9388' 
  AND token = 'qKkLahCJJStlCGoKqgZ7k/FJPtY4sAdZVEGZpZJdLDw=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00022

JSON explain

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