SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '2ed70e084aedc98258831a017a92bb7be0f159c919cb4db045e061f622749074' 
  AND token = 'dLHuSbIZsxL+fPH22DHH5v8WRVBNAfVquj0LFW3ekVc=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00028

JSON explain

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