SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'c1a65f4b3aac86784bad74e01f5122045581023d2923f732766bad37405a9cbf' 
  AND token = 'u9nNktd8J1YlHL4Tx3v5cCDCgjGXYYR75IQISFZ4K0U=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00020

JSON explain

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