SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '87ce0a482dd0b32c19c57d35908b72b0a569c00fdd97aa6beb13883757ac355f' 
  AND token = 'EHhqn3cEW286lQ5GZGn/IXG75Zwl7BYi34PfyT+rlXs=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00030

JSON explain

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