SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '384015197cabf84feb82c9d0e6c90089349451b658af416e75623afeeb422827' 
  AND token = 'nNhDkyhcoe25m47bo4q5xMB5bMBac9F1pGugF14YKNk=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00039

JSON explain

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