SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'a467e5ce19a4f971218bc8578a623377e8517ab288c23c488c787f059ba0ab56' 
  AND token = 'TNHlRkELpgmJvxKsdnFqM2P5x2y2FRQGpBzC0ruvhFY=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00017

JSON explain

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