SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '03c411ce9ee808cc0eed968b10398c9d83d9cfe1fb26e1be64ce7d7d4c311a16' 
  AND token = 'eH7oAR+tmzY9JgRbo9lBZl7uuzlDdydfb8QETOhukg4=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00030

JSON explain

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