SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '8c43a129645f20a9dd7379607ddd75944305f7e8e57386cc55047f271dcdfaae' 
  AND token = 'HEb5pqcEjgQ3hfwJ7MsM5cwHCaJ0ra3FxobR86bwkZM=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00031

JSON explain

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