SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '69bc5cabb1d67acdb91211a7003a112f7e244dd78b809120f21c291373d9a6f0' 
  AND token = 'ug97yO5uq+CtPzLUL3kiY+FhC+jKG5u+fJBoZmuntQQ=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00010

JSON explain

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