SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '31aa0acd89aecd6bdfeccaf4e4f8066be64e574022ca4b2ee626a2e470c40906' 
  AND token = 'WuYM1Nb8dnCvoohTglWbaSiAVfvBqcx1dPqezwngufA=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00017

JSON explain

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