SELECT 
  1 
FROM 
  cscart_multi_declock_keys 
WHERE 
  key_id = '7e3073f67eaf45fd005d597c680e232aab0e08252252320e037a0a6cee20a6ed' 
  AND token = '9B1jOTpaMn46rwoP3trvzhpmfxKd0qwLx0bpulM0F9o=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00028

JSON explain

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