SELECT 
  1 
FROM 
  cscart_aprillock_keys 
WHERE 
  key_id = 'dbba376584bbf290b6ba0fa16ecb07cd4eb20ab20379c876006d8d05df9bac79' 
  AND token = 'LmIifmDDDQX40DnZVHM/k41nv8bBJie165pSp2J/N0c=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00028

JSON explain

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