SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '541c9cee826eec5a2353fe45b9096964c53aac418337f120a59d131daf9a14dc' 
  AND token = 'JDP02erirq2Ic6GcbP3NrKbV2RXENthzYSsCmTeD+Ks=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00027

JSON explain

{
  "query_block": {
    "select_id": 1,
    "table": {
      "message": "Impossible WHERE noticed after reading const tables"
    }
  }
}