SELECT 
  1 
FROM 
  cscart_aprillock_keys 
WHERE 
  key_id = '36b0121ee76586bb1d5e8fb2094987fde3481724ff53b7fb9c4fb7ff1767953c' 
  AND token = 'uX3MCqkBh1xePw+XA2rDEyqpf89Ot2jJLuwlKCYmwr4=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00024

JSON explain

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