SELECT 
  1 
FROM 
  cscart_june_setuplock_keys 
WHERE 
  key_id = 'd11a27fab0677ac9df9989061489a7f1e9c7d15bece9b34059ce10b61dc06320' 
  AND token = 'PCYSS3lRyf+yeahZ4bPpeQ0rGMM+MfrSZ7KPZAB2QdM=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00031

JSON explain

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