SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '11c8719b2646aa870014f3376e888f9996dc39748f35ad3f9d2235f0c79c9ebb' 
  AND token = 'O44Xh2MRcSGoeJinD9ZBoJOhxhKoVwsZRxTeD+37vQs=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00039

JSON explain

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