SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '0902856fb5318e5c5746c17908c810891d2be8430beafd7d49fda524211d3502' 
  AND token = 'WnRilKSqjR4sXrcdvSUO9prChupFGFhRcqg9FJftIxM=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00043

JSON explain

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