SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'f7c6774f52aabac0759f42846bea362dd2eaefe4e262776e9a2227ac4ce3ed59' 
  AND token = 'TPO1c0KsfqMeRqkoSlg4r4DKPOmNuWZ6C4Kb5ne1+/o=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00036

JSON explain

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