SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '478e52b3adba2a0687b72fc70ad730275eecdf28d758cda3a7686f84bd131a17' 
  AND token = 'F4weNc603yBkPRtN3OzAsJvkH3Sgv2UknIE8xbrJ9QI=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00020

JSON explain

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