SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '3fd151f6f53910ceb4dbbf7d23f26087ca58454c5be2dd30f45a4ca9094aadbd' 
  AND token = 'BI2rPlH7okSJTNae3koVYzmoUokAJN5z/sImZHu0nSs=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00019

JSON explain

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