SELECT 
  1 
FROM 
  cscart_multi_declock_keys 
WHERE 
  key_id = 'd7b1cc54f2ace5fcdbf4aa2283735d67aba0699bef15aa1fcc59db9e3adb4cf2' 
  AND token = 'McvBzM2Qvj3cQjGY4PZUUAOXjj1w3hdogn4VMPJzvC0=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00021

JSON explain

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