SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'ed9f7ceda82262eb50832ff9f54e3a49e35fb1fc6e7a2134b3a7f25c464f62b7' 
  AND token = 'bSRYbRH/SRieGz65hGbzNwxWLUJEkip81nM6aYNJaVI=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00041

JSON explain

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