SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '1fdf45fdb81fb49e0d373e6a4eecb4b47780211045155d899e3729f2dc508b93' 
  AND token = 'YnEaq3ZT0/NHGKONwjzCKzKojr533kITadDpyFLPB5Q=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00026

JSON explain

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