SELECT 
  1 
FROM 
  cscart_multi_declock_keys 
WHERE 
  key_id = '076dadc897c4e2569a8f45a1cdca1c7a9dd15579c164ffa0aa557f194a2717cb' 
  AND token = '/YDABwsvJoW0bHFQ2o0fjeB+TGoNnKuCV9ykRd89J5g=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00031

JSON explain

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