SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '9cdf2b4ee3ff081aa16bf4d6671d37469438ab9044f0f99506d238328ea2b9c0' 
  AND token = 'PzvmZVzGgBY80PUDC+UeUJdwPt9yQScjuV/eMVBPbxc=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00030

JSON explain

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