SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'b7cc693ec64901a3ef6cf3d692ea79ecb85185cd4e827cb48d2fd253959eda92' 
  AND token = '2AZerR/lLh7pv5dy4CJr5nNed2LwJZ633RjyxPbGnv4=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00033

JSON explain

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