SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'c38c5bcff7e2b8ab4af79bbfcabdc591563ec7302088d6f9b7d99a90cb38469c' 
  AND token = 'XvuSfUPILL1KGsLgRh2oAP5KGAiFRorqulemWbzV0j4=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00028

JSON explain

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