SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '9cd32a6403aa6093dbee1b825f8dfb49683bc155ce192cedf01e3ab9625989c8' 
  AND token = 'z+4sXQeu/0E4s26lpuhj7bnHokHaqvHJOZVjzaw77Co=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00023

JSON explain

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