SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '972cf91d42a27d6d5f49bea906c866c34f62e0a9aa196c35d8b076b48926a9d7' 
  AND token = 'dJV+Yi/P8f842ojJIOnpCwBr+Co1vlsX9ZulH0O+Kqk=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00017

JSON explain

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