SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '27526c411cb35cc4d048d91857553895dd5f6bc93dbc982e15dedd086d4ff4f9' 
  AND token = 'sXkFBtVkdTCA0deJT4P4fqJr7n5juFyRYr8Qj/x9anc=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00037

JSON explain

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