SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '16dae97b3e58d0913bf3f8fb4f5054e49e2b31808b0dd99ff36709d935dd1efa' 
  AND token = 'T5lN1keTXLPoJPIxfUL9nYJly/4TrngYhSoFYxk8br4=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00021

JSON explain

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