SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '4cb4eef5413113e40c13a2666776601effa2cada5fa6cc009ff55260eaaaef11' 
  AND token = 'MBmulQBF2QBWAQNjmBR0fU9VsGlgUABnsvEOgqMHmQs=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00023

JSON explain

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