SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '56e82afc006eda279f6fcf38d272b9855794b3531bb12b1b7c27c8f999d63c48' 
  AND token = 'w9lGHYN1kCY6PHXKp83WcfBWcGssK19VZR84NVWJUGI=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00015

JSON explain

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