SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '9837d63ca179f6533b1f32876793524284a065ecb7257cedacb2f46eb62acf0a' 
  AND token = 'VdAkBdBnYUpaBQC1qxttz0CB37ORGWO8EIUxl736qKI=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00018

JSON explain

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