SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '948e1759b7272929cfb4b0640779d9b7bebe94c634cde99bbb162adbb3a0ff66' 
  AND token = 'a3ftVsOZq3WVJGThEJ27ye7A4eD0ULZtDvwfDnHI19c=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00033

JSON explain

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