SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'e8ecec75c8681332ac0b8d8dc278c7227b4f9dd5e7af2311ae6c2596b2181425' 
  AND token = 'lSrhvb5jfuqrgsAn4zL5NiEGWlqBtUEGvMoTRj1y2ss=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00038

JSON explain

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