SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '4d66f3cfc501bbb225536ff7725174515b0a3ce464a5f1b3f264ab1d9f5f2ab1' 
  AND token = 'fJPJlmGCprVJeV/7FnCQoU8ESMeCKiCyZq0Lka6DqlE=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00027

JSON explain

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