SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'c3e4c5a7224ea1ee621de3f769fb516a942c9e54aafc70b2408f8d7d0705b581' 
  AND token = 'FVztq2MhjOQkIr1B1kBfVBqSExt6H67LxGodJhn9BgE=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00037

JSON explain

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