SELECT 
  1 
FROM 
  cscart_aprillock_keys 
WHERE 
  key_id = 'ef9c4fb317532f97d4002abb36795fafea558202217f637a50c5805d895c8a2a' 
  AND token = 'sedQWViXVorEj1QKuFPmkyPOzbzYFshkOHZD2S51tq4=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00025

JSON explain

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