SELECT 
  1 
FROM 
  cscart_aprillock_keys 
WHERE 
  key_id = 'f876b847885ae245a62608f2792f5a1a57b0f37413dfb6b3641184169377f6dd' 
  AND token = '3mXzrX09mjE3oKxtsTWnu1GXuDceIUB+wukVUadS3gE=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00037

JSON explain

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