SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '0c1b221aa89e7e656ad5d0e93c296eff09d31d3314f991e6b88823ecf419aad9' 
  AND token = 'DJbqBzq6jSBm/cys6MOs8lZxsh4wob/lYuwEnkXhUrI=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00035

JSON explain

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