SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '964d641bf4d5e508df6d1925e4fc066a69c773675438e513f2a3c09ebb19f0fe' 
  AND token = 'UvoRYLJYZnkNWY4Fv+BrxMBHOC1gWzx7uTcU4Unf834=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00022

JSON explain

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