SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '27f888b5af3298a879ac2d3073c8d77f3804ca0cd67c3e2847a03f7b46eff350' 
  AND token = 'Cqgdtzbxtg+8MnkJCni03ztfXtMTga81u8wsNDAM8WI=' 
  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"
    }
  }
}