SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '35b9fbc6b81d80fd8a46b62b4cc7426f98901136be570d8c2a6527096d65fd4d' 
  AND token = 'svAEQgXMveHxdq9xnAnrtGKDaNlyofqsiSzqeBhzxIc=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00032

JSON explain

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