SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '733dab62654ab5e5872f734e7c0b148d8bdb8bcdfcfe288202691cb3d286d24f' 
  AND token = '6EOaFqxiWLh86J/G4GiYD86TekC7rS/NmAJObAuV754=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00037

JSON explain

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