SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '4affdc89901b205a1cf8fbffe32cdd3146a466517f91accea7d106b2d9c012cb' 
  AND token = 'FBiq4AuszQlnJc0Sqcnt6k/2NuaTmxl128+9AR65jIw=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00035

JSON explain

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