SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '0cd5ee332a83bccb4edca491b9863b8da46cb4c4dae5fddaaf2f6264bace2a1a' 
  AND token = '1swSuIt2jVt1VLwtuHXGnDmVerZwNFKrS/j7XNGeza8=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00031

JSON explain

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