SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'f20f844baf33e84c8dee0a488c1c2c160e4c099484ecdec8a9c45c468546d17d' 
  AND token = '1wnsbmwPKIRIjFPSvxylvsnl4+yo/5FdXmdLNqHMhJ4=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00040

JSON explain

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