SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '1f831ee556c274d472d6e2228d0f4fad970a7b022f8e8969db78bdf6c24f47cc' 
  AND token = 'zzQmoyMesbafLCZ/q7Oyyj1LknYwsFvUlPgt2CZGsUo=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00020

JSON explain

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